Introduction: Simple STEAM Project: 3D Printed Keychain

Are you looking for a fun project to introduce students to 3D printing and modeling?

I have done this activity in our makerspace with middleschoolers and with college kids. It is a simple way for learners of all ages to get started with TinkerCAD and using the MakerBot 3D Printers!

Supplies

Equipment: Makerbot PLA Printer or other 3D Printer

Materials: PLA Filament, keychain rings (optional)

Step 1: Getting Started With TinkerCAD

Option 1: Individuals each create an account

Option 2: Instructor provides access via a Class

  • Ahead of time, the instructor creates a TinkerCAD class: https://www.tinkercad.com/dashboard?type=classes
  • Once the class has been created, click on its name to view and add students
  • Add students by providing a name and a nickname (these can be generic, such as Student01, or specific to your roster.
  • Provide the class link and the nickname to your students to use for log-in
  • Benefits of this option:
  • no email access needed for students to sign in
  • instructor can easily view all designs created by the students
  • if desired, the instructor can create a base design for the students to Tinker

Step 2: Modeling the KeyChain

  • From the right drop-down menu, choose "Design Starters"
  • Then, choose the sub-category "Letters and Numbers"
  • Click and hold on a block letter and drag it onto the workspace
  • Change the view to Top View by clicking on the cube to the left of the workspace
  • Optional: I like to change the view to Flat View to turn off any perspective
  • Select a new block letter and drag it to overlap with the first Block Letter
  • Note: The more the letters overlap, the stronger the bond will be. Change the Snap Grid values (at the bottom right of workspace) and nudge the letter up/down or left/right using the arrow keys to get it in the right place.
  • Repeat until name is complete

Step 3: (optional) Fun Shapes

  • From the right drop-down menu, choose "Basic Shapes" or "Characters" or "Shape Library"
  • Browse shapes and select something to add to the keychain
  • Drag it into the workspace, resize, rotate and place on your keychain
    • Note: since you will need to resize most shapes and rotate characters, I recommend this option for someone who is already comfortable with TinkerCAD or for more advanced students.

Step 4: (optional) Adjusting the Letter Height

The block letters are the perfect size to make small keychains. So there is no need to resize the letters. If you wish to create a sense of dimension, you can edit the height of the letters by following these steps:

  • Click on the cube to the left to change the perspective to the Top/Front view
  • Click on a letter and then on the white cube in the center
  • Type a "3" in place of the "4"
  • Repeat other letters you wish to alter

Step 5: Adding the Keychain Ring

Use an "O" for the Keychain Ring.

  • Drag an "O" into the proper location.
  • Change the pespective to be able to easily view the "O"
  • Clicl on the letter, and then subsequently on the white sizing cubes. Change the dimensions by clicking on and retyping the numbers.
  • Resize it to "3" x "3" in width and length; and "2" in height.
    • Note: The default dimensions for TinkerCAD are mm. So we are making a 3mm x 3mm circle with a hole that is approximately 1mm in diameter.

Step 6: Export STL File

  • Type "Ctl + A" or drag and click with the mouse to select all the shapes in your workspace
  • Type "Ctl + G" or click on the Group icon to group all the shapes into a single one
    • Note: The color will change; colors do not export with STL files
  • Click on the "Export" button
  • Choose to export an "STL" for 3D Print

Step 7: Prepare File for 3D Printing

Do this step for your students, or guide them through the process themselves!

  • If you have a Makerbot printer, visit https://cloudprint.makerbot.com/ to prepare your print.
  • Note: use another program for other 3D printers
  • Log in at the prompt (I recommend using the Google Log-In)
  • Click "Print Preparation" at the top right corner
  • Click on "Add Models", then choose "Add File"
  • Browse for the STL file you exported from TinkerCAD

Step 8: 3D Print Settings

  • Select the Makerbot printer
  • Select the correct extruder
  • Select the desired base layer:
  • Base layers are required for printers without heated beds:
  • The default "Raft" will create a smoothe bottom surface
  • "Padded Base" will print quicker and will waste less plastic, but will have a base layer with thicker extrusion lines.
  • Printers with heated beds to not require any base layer
  • Change the number of shells to 4 for a stronger key chain ring
  • Change the infill to 0.2 for a stronger key chain in general
  • Select "Export" and save the file to a USB drive

Step 9: Print Your Keychain!

  • Plug the USB Drive into the Makerbot
  • Select to print from USB
  • Choose the file you saved to the USB Drive
  • Start the print!